[guzzler]

Quote:

Originally Posted by Nisbeth Any trouble soldering the PCM2702?

none at all, I bought some 28awg SMD solder, but didn't need it: used 21awg Cardas silver solder excessively then used a desoldering pump to take off the excess. Same as the solder wick technique, but I've never been any good at using desoldering braid. The worst bit was lining the little legs up on the right pads.

The boards are very nicely made, I was recommended the manufacturer by aos and I can only say it was a good recommendation!

edit: yep, battery powered, a steady 5.00V from the first regulator. Didn't want to prod around too much with the multimeter to measure the switching output with big prongs, will do that soon though. I assume the 3.3V output was good as the PCM2702 powered up fine

g

 

[doobooloo]

I think I posted earlier requesting a set or two but I am not too sure; in case I didn't, is it too late to lay my hands on a few of these boards?

Thanks!

 

[guzzler]

Quote:

Originally Posted by doobooloo I think I posted earlier requesting a set or two but I am not too sure; in case I didn't, is it too late to lay my hands on a few of these boards? Thanks!

not at all, the more the merrier

we'll probably be sorting out parts kits minus the semiconductors, and a couple of other things as well.

Did some more measurements, output from switcher is 5.47V, 5V = 5.00V, 3.3V = 3.28V so everything is good on the power side of things

g

 

[hashman]

I am sorry if it is too late for me to ask for a board as well. I've been oogling this project for a while and was too lazy to register at head-fi. if possible please count me in for at least one.

hashman

 

[AdamZuf]

why didn't anyone ask how it sounds

 

[ITZBITZ]

I believe that gz is waiting on the coupling caps before hooking it up to an amplifier.

 

[AdamZuf]

how about making another version of the board so we'll have a coaxial output? it is quite a useful thing to have.. i think that the Xitel can't transmit 44.1khz.

 

[ITZBITZ]

Quote:

Originally Posted by AdamZuf how about making another version of the board so we'll have a coaxial output? it is quite a useful thing to have.. i think that the Xitel can't transmit 44.1khz.

The part used in this project does not have a digital output. There are a number of designs that use the 2902, a part that has S/PDIF output.

 

[AdamZuf]

Quote:

Originally Posted by ITZBITZ The part used in this project does not have a digital output. There are a number of designs that use the 2902, a part that has S/PDIF output.

is anyone working on these designs ATM?

 

[00940]

adamzuf : http://hepso.dna.fi/misc/pcm2902/PCM2902_usb_dac.html

 

[guzzler]

we've got the parts mixed up here folks... the PCM2702 is what this board uses, it's the PCM2704 has the S/PDIF output. I'll put together a layout based on that if folk want to see one, I won't be getting any made though

g

 

[ITZBITZ]

More Pictures

 

[ITZBITZ]

Voltage test: 5V reg = 4.98, 3.3V = 2.99, output from Maxim IC: 5.51

Connected to USB powered from 3x1.5V AAA batteries (what I had on-hand)

Recognized by Windows XP, no drivers needed, sound device added. Setup Foobar to point to it, adjusted volume with control panel to max output level (no attenuation at the DAC). I guess I didn't fry the 2702.

Connected to PPA (the big-un') -> DT880

Music comes out. Need to spend some time listening, but initial results seem favorable.

 

[00940]

Quote:

Originally Posted by ITZBITZ Voltage test: 5V reg = 4.98, 3.3V = 2.99, output from Maxim IC: 5.51

5.51 is a bit high, the regulator needs only 200mV to drop. Something along the line of 5.2 would be better and would save some battery life. It's just a matter of tweaking a bit the value of a resistor.

 

[guzzler]

looking good ITZ, still haven't got my coupling caps yet, I'll get onto the HiFi Collective about it, but I'm glad it works!

I've finally worked out how to make it bus powered with a decent quality of supply, and (as always) it's so simple: jumper from a pad on R7 (which is otherwise unused) to the +ve side of the BATT connector. That way the 5V USB power gets stepped up by the switcher then regulated at 5 and 3.3V levels to provide a reasonably clean power source, though probably still not as good as batteries!

g